From: Kalle Valo <kalle.valo@iki.fi>
To: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-wireless@vger.kernel.org, Christian Lamparter <chunkeey@web.de>
Subject: Re: [PATCH 5/5] p54spi: use firmware/DMA bug workaround that work under hight load in p54spi_rx
Date: Mon, 18 May 2009 21:53:05 +0300 [thread overview]
Message-ID: <87tz3i9ram.fsf@litku.valot.fi> (raw)
In-Reply-To: <1242601355-3178-6-git-send-email-jcmvbkbc@gmail.com> (Max Filippov's message of "Mon\, 18 May 2009 03\:02\:35 +0400")
Max Filippov <jcmvbkbc@gmail.com> writes:
> Under high load first data word, read after available data size
> is sometimes lost in p54spi_rx. It seems to depend on frequency
> of interrupts and latency of data read request relatively to
> 'data available' interrupt. The worst consequence of this bug
> is loss of packet transmission acknowledgement, which in turn
> causes overflow of tx queues and permanent link loss.
>
> Read data size and first data word in one SPI transaction.
> No packets from LMAC should have length less than 1 word,
> so this shouldn't interfere with the next read transaction.
There is a bug in omap2_mcspi which corrupts some DMA transfers, I don't
know if the bug you see is this one or something else. I'll send the
patch to linux-omap sometime later this week.
--
Kalle Valo
next prev parent reply other threads:[~2009-05-18 18:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <0001-p54spi-fix-incorrect-access-sequence-to-DMA_WRITE_C.patch>
2009-05-17 23:02 ` [PATCH 0/5] p54spi: fixes to achieve link stability Max Filippov
2009-05-17 23:02 ` [PATCH 1/5] p54spi: fix incorrect access sequence to DMA_WRITE_CTRL in p54spi_spi_write_dma Max Filippov
2009-05-17 23:02 ` [PATCH 2/5] p54spi: cosmetic fixes: use even byte count in SPI write; drop unused interrupt status read Max Filippov
2009-05-17 23:02 ` [PATCH 3/5] p54spi: return status of p54spi_wakeup Max Filippov
2009-05-17 23:02 ` [PATCH 4/5] p54spi: always call p54spi_sleep in p54spi_tx_frame if p54spi_wakeup succeeded Max Filippov
2009-05-17 23:02 ` [PATCH 5/5] p54spi: use firmware/DMA bug workaround that work under hight load in p54spi_rx Max Filippov
2009-05-18 18:53 ` Kalle Valo [this message]
2009-05-18 21:21 ` Max Filippov
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